Strange power question

Archived from groups: comp.sys.laptops (More info?)

Hallo! I have a Compaq armada m300 600Mhz with a power unit rating of 18,5
Volts
and i was experimenting and tried a 12Volt 88Ah car battery as power
source.

To my surprise it worked and ran for two days, until the voltage was 11,3
volts.

Can somebody explain why??

Because when i use smaller batteries it stops running at 15,4 Volts.
Strrange or what???

--
Using M2, Opera's revolutionary e-mail client: http://www.opera.com/m2/